Meso-scale water structure in the southern Baltic in the summer of 2006

Sequences of high resolution transects of temperature, salinity, and oxygen concentration measured from the Arkona Basin through the Bornholm Deep and the Slupsk Furrow to the Gulf of Gdansk in the summer of 2006 are discussed. The measurements were made using U-tow CTD probe with an oxygen sensor. The measurements revealed peculiar features in the distributions of thermohaline and oxygen fields. The data allow us to describe one of the possible scenarios of water interaction in different basins during warm season in the stagnation period. This scenario is characterized by the lack of any noticeable mass exchange between different basins. At the same time, evidences of previous intrusions are notable in the Bornholm Basin. The hypothesis is put forward that intrusions of saline warm water from the Arkona Basin are locked by the waters from the intermediate layer. A significant decrease in oxygen concentration between the two basins in the eastward direction at the same isopycnal surface is also noted.